This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| n | a(n) |
|---|---|
| 1 | 7 |
| 2 | 55 |
| 3 | 595 |
| 4 | 727 |
| 5 | 787 |
| 6 | 5995 |
| 7 | 59995 |
| 8 | 72127 |
| 9 | 72727 |
| 10 | 78187 |
| 11 | 78787 |
| 12 | 599995 |
| 13 | 5999995 |
| 14 | 7212127 |
| 15 | 7218127 |
| 16 | 7272727 |
| 17 | 7278727 |
| 18 | 7812187 |
| 19 | 7818187 |
| 20 | 7872787 |
| 21 | 7878787 |
| 22 | 59999995 |
| 23 | 599999995 |
| 24 | 721212127 |
| 25 | 721272127 |
| 26 | 721818127 |
| 27 | 721878127 |
| 28 | 727212727 |